The 49-year-old actor has starred as Bruce Banner/The Hulk in the Marvel Cinematic Universe since 'The Avengers' and is reprising his role in the third 'Thor' movie alongside Chris Hemsworth as the titular character.

'Thor: Ragnarok' marks the first time the MCU will feature a lead female villain, Hela - played by Cate Blanchett and the film also features another strong-female Valkyrie (Tessa Thompson) and Ruffalo has nothing but praise for his co-stars.

He said: ''It's great that we have Blanchett and Thompson, these two amazing, powerful, strong, beautiful, intelligent women, playing these two important, integral characters in this movie.

''We have Hela, played by Blanchett. She has all the power, all the strength, all the talent of any of the other gods, but with all the rage.

''She's angry, and she wants to come back and take what she feels is rightfully hers. Except that she's been pushed so far into the darkness that she's become dark. She's now the manifestation of death. Then you have Valkyrie, played by Thompson. She is another female presence who didn't feel welcome. She's a powerhouse and a brilliant fighter. She's as equally as powerful as Thor. She's a warrior. Valkyrie is one of the people who ended up banishing Hela from Asgard.

''But she's also lost faith in the patriarchy and the elite power structure.''

Director Taika Waititi recently teased there will be a new-look Thor in the latest film and revealed he is to be ''grubbier'' than previously.

Taika shared: ''He's a lot grubbier. I think everyone's a bit too shiny and clean in the other films. I love heroes that really go through ordeals and then come out the other end completely changed. They come out the other side and they've been through the ringer.

''We do a lot to this character in the film. A lot of people want to see Ragnarok and know what it means; but, to me, Ragnarok means stripping down the establishment and then building it up in a new way. Ragnarok is what we're doing to the character and to the franchise and to the story.''